The objective of the present proposal is to synthesize and evaluate fluoroprostaglandins related to natural PGF 2alpha as potential luteolytic agents. We plan to synthesize in optically pure form 13-fluoroPGF2alpha, 12,14-difluoroPGF2 alpha, 12-fluoromethylPGF2 alpha, (15R, 16S)-12,16-difluoroPGF2 alpha, (15R, 16R)-12,16-difluoroPGF2 alpha, and 12,16,16-trifluoroPGF2 alpha.